Redox reactivity of selenium in environmental geomedia (REDOX)

Summary

The interactions with redox-active solid phases –notably with Fe(II) and S(–II)-bearing solids- mediate the oxido-reduction kinetics of selenium oxyanions, playing an important role in the control of selenium speciation. Se(VI) was found to be metastable (far from thermodynamic equilibrium) and to co-exist in different oxidation states in the Callovo-Oxfordian pore waters. The reduction of Se(VI) by magnetite has been described to include different steps (adsorption, reduction to Se(IV) and further reduction to less soluble Se phases). At present it is not clear whether the Se(VI) initial adsorption or its reduction to Se(IV) are concomitant or not.

The goals of REDOX are:

1. To shed light on the mechanisms driving the interaction of Se(VI) with magnetite, pyrite, and siderite
2. To investigate the impact of ubiquitous inorganic ligands such as sulfate and carbonate

Publications

Contributions to conferences (Talks and Poster)

2023